The international guide to gender-inclusive writing
I only just found this huge guide put together by the Gender-inclusive Language Project and published by UX Content Collective.
Adobe's guidelines on inclusive UX writing
Everyone building products has the responsibility to prioritize inclusion. Writing the language inside products is an extremely powerful way to do so.
Want to Create Inclusive UX Content? Avoid These Words
Lots of useful advice in this blog post by Chinwe Uzegbu, published on UX Planet. These are the small details that make a significant difference if you want to write in a way that does not exclude or alienate people.